Nice's Pasteur hospital said the man who died Thursday had been on life support since the day of the attack.

The local newspaper Le Messager said he was a 56-year-old from France's eastern Haute-Savoie region, whose wife and son were also killed in the attack and whose 14-year-old daughter remains in hospital.

President Francois Hollande is facing mounting demands to improve security after a string of jihadist attacks, dating back to January 2015, when gunmen stormed the offices of the Charlie Hebdo satirical magazine and a Jewish store.

Then in November, 130 people were killed at restaurants, bars and a concert hall in Paris.

In another attack just last week, ISIS terrorists broke into a church in Normandy and beheaded a priest.